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Infertility Hot Topics in Fertility Care Fertility and Aging The “ticking of the biological clock” has been the subject of much media attention. It is a crucial subject. Anyone in reproductive medicine is painfully aware of how much more difficult achieving a healthy pregnancy can be as a woman reaches the late 30’s. Two important points need to be understood. Firstly, you must be aware that a woman’s ovaries may age using a different clock from that used by the rest of her body. That is, her age may be 35 but her ovaries may function like those of a 40 year-old. The reverse is occasionally true, e.g. a 42 year-old functioning like a 30 year old, but is much less likely. Why this is true is not clear. What is clear is that to delay childbearing much beyond 30 carries a risk of not being able to use one’s own eggs to have a baby. Secondly, it is important to know that ovarian age can be tested. Hormone testing is used to measure the functioning level of a woman’s ovaries. The test I use is called the clomiphene challenge test (CCT) which involves taking tablets and having blood drawn on certain days of the cycle. This can give us a measure of where the person is on the biological clock. What Can Be Done When the Biological Clock Runs Down? At present the only therapeutic option is to utilize the oocytes (eggs) of a another woman. That person is known as the “donor”. The patient is the “recipient”. The donor can be a family member, friend, or a person recruited by an agency for that purpose. The process involves in vitro fertilization. Oocytes are removed from the donor’s ovaries by needle. Those oocytes are then fertilized in the laboratory by the sperm of the husband of the recipient. After developing in the laboratory, the embryos are placed in the uterus of the recipient. Her uterus will have been prepared for this moment using hormones. In the future, it will be possible to borrow only part of donor eggs. The genes (nucleus) of the patient will be inserted into the donor’s eggs. The donor’s genes would have been removed. This means that the baby will have the mixture of genes which would happen if only the patient’s eggs were used. |
